[OmniOS-discuss] Pliant/Sandisk SSD ZIL

[Marion Hakanson]

Thanks for everybody's comments.  More data from folks doing similar stuff
is always welcome.


Marion Hakanson wrote:
>> Out of curiosity, what HBA is being used for these drives (and slog)
>> in this R720xd, H710 or H310?  Something else?
> 
Derek Yarnell wrote:
> This is a R720xd shipped with a pristine LSI card (mine even came with
> IT firmware).  You will need to talk to your rep but they can do it.  My
> hope here was to get a fully supported OmniOS box from Dell which the
> biggest problem was before making me take a H710/H800 card.  While we
> have been successful running ZFS with a R510 w/ H700s drives all in R0
> and setting zfs_nocacheflush it just isn't right.  We have also never
> gone more than 9 data drives with the R0 configuration (also this has
> been mostly on Nexenta not Omni).

We have quite a few R710's with the PERC/6i internally, but for those used
as ZFS file servers, the PERC's only apply to the two boot drives, where
the "R0" approach is relatively painless.  BTW, with these RAID HBA's that
have non-volatile caches, you shouldn't need "zfs_nocacheflush" -- the OS
recognizes when a cache is NV, and won't send a flush.  That's been my
experience since late 2008, anyway.

We've had mixed results when asking Dell to send us LSI-branded HBA's.
Sometimes they'll do it, sometimes not.  Lately, we've gotten them to
sell us Dell branded SAS 6gbps HBA's for use with external MD1200's,
and those seem to be working just like LSI 9200-8e's & 9207-8e's.

Anyway, thanks for the suggestion, I'll see what our rep can do for the
internal HBA.  That would be much nicer than having to deal with possible
H310 glitches.


> The R720xd flex bays are no longer internal but in the back of the
> machine[1].

Well, that's close enough to "internal" for my purposes (:-).  We have
an Oracle X4270-M2 configured like that, now 3+ years old.  Very nice
layout, it's a pity they stopped selling them to mere mortals.


> I actually will test some spare DC S3700 drives as the slog
> devices that we have for a Ceph cluster in this in the next few days and
> will report back on this thread.

Cool, I look forward to seeing what you find out.

Thanks and regards,

Marion